XXIV International Mineral Processing Congress, Beijing, Çin, 24 - 28 Eylül 2008, cilt.1, no.1, ss.300-309
Surface roughness and acuteness are known as the two of the main
properties of the particle morphology affecting the behavior of the powders in
the process. Since the techniques used for the morphological characterization
of powders by 2-dimensional microscopic measurement from the polished
sections that have some disadvantages, the 3-dimensional analysis has often
relied on measurements of particle morphology.
A review of literature data was presented for high-grade barite and pyrite
particles ground by ball and autogenous mills to determine the morphological
properties using a new 3-D approach based on BET nitrogen gas adsorption
and Permaran methods.
Micromeritics Flowsorb II 2300 instrument which employs BET nitrogen
adsorption technique was used for the specific surface area measurements
and the roughness of the particles. Permaran (manufactured by Outokumpu
Oy) was used for the measurements of airflow resistance of powder samples
for the acuteness. Spherical glass beads were used as reference sample for
the acuteness measurements. The obtained parameters, which are surface
roughness and acuteness, were correlated with the floatability performance of
those mineral particles.
The flotation performances of those particles ground in different mills (ball and
autogenous) were also evaluated by a Hallimond tube.
The results showed that lower roughness and acuteness values caused
higher flotation recoveries for both barite and pyrite particles that were tested
independently in different type of the mills. In other words; particles with
smooth surfaces resulted in better floatability for barite and pyrite minerals